Prior U.S. Pat. No. 4,320,678, issued Mar. 23, 1982, to Michael J. Volk, discloses in drawing FIGS. 12 through 16 a guide means for the unsupported end of a sabre saw blade which travels with the saw blade on its path of movement through a workpiece being cut by the blade. The guide means shown in two forms in the referenced prior patent is in the form of a small guide plate which traverses a pair of parallel rails attached to a power tool accessory table. In each disclosed form of the saw blade guide means, a special non-conventional sabre saw blade is required. In one form, the normally unsupported end of the saw blade is bifurcated and the body of the blade is wider than a standard type blade. In the second form, the unsupported end portion of the sabre saw blade comprises a toothless extension of the blade, causing it to be non-conventional.
The present invention has for a main objective to provide a follower guide for any standard or conventional sabre saw-type blade, thus obviating the necessity for manufacturing a special non-standard blade which is both costly and impractical.
The term "sabre saw" referred to herein is used only to describe the technique of operation of a saw blade with which the follower guide can be used. This invention may be used with any saw wherein one end of the saw blade is unsupported or cantilevered. Such saws are also referred to in the trade, for example, as jig saws.
Another object of the invention is to provide a follower guide for a sabre saw blade which is spring-urged into constant engagement with the rear toothless edge of the blade near its unsupported end so as to stabilize the saw blade in all directions during its passage through a wood piece being cut by the blade. The invention prevents twisting, bending and lateral displacement of the sabre saw blade and therefore assures a clean precision cut through a workpiece.
Another important object of the invention is to provide a sabre saw blade follower guide which is compatible with various types of saw table structures equipped with power tool guide means, with or without associated protractor means. The follower guide is in the form of an elongated blade element having a forward end saw blade guiding notch. The blade element can be installed flush with the workpiece support surface of a saw table or platform.
Still another object of the invention is to provide a spring-biased follower guide for a sabre saw blade which can be retracted and cocked in an inactive position relative to the sabre saw blade.
A further object is to provide a sabre saw blade follower guide of the mentioned character which can be utilized on a table structure equipped with sabre saw guide rails which are used in two different operating modes, raised and fixed or floating and resting on a workpiece, the present invention being compatible with either mode of use.
Other features and advantages of the invention will become apparent to those skilled in the art during the course of the following description.